Excerpt from Washington Post Article June 2018:
Of course, in the U.S. and many other countries, smiling is a common, reflexive gesture of goodwill.
There is, indeed, truth to the “smiling gap”: In our psychology research, we’ve noticed a striking difference in how often people smile in the United States when compared to Russia. To Americans, it might be easy to assume that this says something about Russians – that they’re an unfriendly, callous people.
But that’s not the case at all. Instead, it’s worth looking at why certain expressions, like smiling, become a key part of social exchanges in some cultures and not others.
As far as we can tell, there are two likely explanations for the smiling gap: how people in different cultures communicate with one another and cross-cultural differences in personality or temperament.